Interpolymers suitable for use in hot melt adhesives and processes to prepare the same

ABSTRACT

The present invention relates to an ethylene/α-olefin interpolymer product comprising at least one α-olefin interpolymerized with ethylene and, characterized in at least one aspect, as having improved properties when utilized in a hot melt adhesive formulation. The invention also relates to a process for manufacturing the interpolymer product wherein the process comprises employing two or more single site catalyst systems in at least one reaction environment (or reactor) and wherein the at least two catalyst systems have (a) different comonomer incorporation capabilities or reactivities and/or (b) different termination kinetics, both when measured under the same polymerization conditions. The interpolymer products are useful, for example, in applications such as hot melt adhesives, and also for impact, bitumen and asphalt modification, adhesives, dispersions or latexes and fabricated articles such as, but not limited to, foams, films, sheet, moldings, thermoforms, profiles and fibers.

REFERENCE TO RELATED APPLICATIONS

This application is a U.S. Divisional Application of U.S. applicationSer. No. 10/567,142, filed Feb. 6, 2006 now U.S. Pat. No. 7,531,601 nowallowed, which is a U.S. National Stage Application, under 35 U.S.C.§371, of International Application No. PCT/US04/30706, filed on Sep. 17,2004, which claims the benefit of U.S. Provisional Application No.60/504,412, filed on Sep. 19, 2003.

FIELD OF THE INVENTION

The present invention relates to an ethylene/α-olefin interpolymerproduct comprising at least one α-olefin interpolymerized with ethyleneand, characterized in at least one aspect, as having improved propertieswhen utilized in a hot melt adhesive formulation. The invention alsorelates to a process for manufacturing the interpolymer product whereinthe process comprises employing two or more single site catalyst systemsin at least one reaction environment (or reactor) and wherein at leasttwo catalyst systems have (a) different comonomer incorporationcapabilities or reactivities and/or (b) different termination kinetics,both when measured under the same polymerization conditions. Theinterpolymer products are useful, for example, in applications such ashot melt adhesives, and also for impact, bitumen and asphaltmodification, adhesives, dispersions or latexes and fabricated articlessuch as, but not limited to, foams, films, sheet, moldings, thermoforms,profiles and fibers.

BACKGROUND OF THE INVENTION

Ethylene homopolymers and copolymers are a well-known class of olefinpolymers from which various plastic products are produced. Such productsinclude hot melt adhesives. The polymers used to make such adhesives canbe prepared from ethylene, optionally with one or more copolymerizablemonomers. One process used to produce ethylene homopolymers andcopolymers involves use of a coordination catalyst, such as aZiegler-Natta catalyst, under low pressures. Conventional Ziegler-Nattacatalysts are typically composed of many types of catalytic species,each having different metal oxidation states and different coordinationenvironments with ligands. Examples of such heterogeneous systems areknown and include metal halides activated by an organometallicco-catalyst, such as titanium chloride supported on magnesium chloride,activated with trialkylaluminum compounds. Because these systems containmore than one catalytic species, they possess polymerization sites withdifferent activities and varying abilities to incorporate comonomer intoa polymer chain. The consequence of such multi-site chemistry is aproduct with poor control of the polymer chain architecture, whencompared to a neighboring chain. Moreover, differences in the individualcatalyst site produce polymers of high molecular weight at some sitesand low molecular weight at others, resulting in a polymer with aheterogeneous composition. The molecular weight distribution (asindicated by M_(w)/M_(n), also referred to as polydispersity index or“PDI” or “MWD”) of such polymers can be fairly broad. For somecombinations of heterogeneity and broad MWD, the mechanical and otherproperties of the polymers are sometimes less desirable in certainapplications than in others.

Another catalyst technology useful in the polymerization of olefins isbased on the chemistry of single-site homogeneous catalysts, includingmetallocenes which are organometallic compounds containing one or morecyclopentadienyl ligands attached to a metal, such as hafnium, titanium,vanadium, or zirconium. A co-catalyst, such as oligomericmethylaluminoxane (also called methylalumoxane), is often used topromote the catalytic activity of the catalyst.

The uniqueness of single site catalysts, including metallocenes, residesin part in the steric and electronic equivalence of each active catalystsite. Specifically, these catalysts are characterized as having asingle, stable chemical site rather than a mixture of sites as discussedabove for conventional Ziegler-Natta catalysts. The resulting system iscomposed of catalytic species which have a singular activity andselectivity. Polymers produced by such catalysts are often referred toas homogeneous- or single site-resins in the art.

A consequence of such singular reactivity is that by variation in themetal component and/or the ligands and ligand substituents of thetransition metal complex component of the single site catalyst, a myriadof polymer products may be tailored. These include oligomers andpolymers with molecular weights (Mn) ranging from about 200 to greaterthan 1,000,000. In addition, by varying the metal component and/or theligands and ligand substituents of the single site catalyst, it is alsopossible in ethylene alpha olefin interpolymerizations to vary thecomonomer reactivity of the catalyst, such that very different levels ofcomonomer are incorporated at a given comonomer concentration. Thus itis also possible to tailor the density of the product from products withhigh comonomer incorporation (resulting in densities lower than 0.900g/cm³), through to products with almost no comonomer incorporation(resulting in densities greater than 0.950 g/cm³), both at the samecomonomer concentration in the reactor.

One method of utilizing this variation in single site catalystreactivity is to employ two or more such catalysts in conjunction with amultiple reactor configuration, to produce so-called in reactor resinblends which are a combination of products made by each catalyst. Inthis case, there exists the ability to: i) control the polymerizationconditions in each reactor independently, ii) control the contributionof each reactor product to the final polymer composition (the so calledreactor split ratio) and iii) supply each reactor with a single-sitecatalyst, allows such a process to produce a wide range of polymericproducts that are combinations of each reactor product. The ability toproduce such in-reactor blends as opposed to post reactor blending ofseparately prepared components has definite process, economic andproduct flexibility advantages in applications calling for a productwhich cannot be made in a single reactor single catalyst or dual reactorsingle catalyst configuration.

In addition, the mutual compatibility of single site catalyst mixtures(as opposed to a mixture of a single site and traditional Zieglercatalyst) also allows for the possibility of producing a broad range ofin-reactor blend products in a single reactor, even under the samepolymerization conditions by introducing single site catalysts ofdiffering comonomer reactivity and/or termination kinetics into thereactor, and varying their relative amounts to yield the desired finalpolymer properties. In this mode, in-reactor blends may also be preparedwhich again are otherwise unavailable except by post reactor blending ofseparately prepared components.

There a number of examples of both types of products and processes inthe prior art. For instance, U.S. Pat. No. 5,530,065 (Farley et al.)discloses heat sealed articles and heat sealable films comprising apolymer blend of a first polymer having a narrow molecular weightdistribution and composition distribution and a second polymer having abroad molecular weight distribution and composition distribution.

U.S. Pat. Nos. 5,382,630 and 5,382,631 (Stehling et al.) discloseslinear ethylene interpolymer blends with improved properties made fromcomponents having a narrow molecular weight distribution (Mw/Mn≦3) and anarrow composition distribution (CDBI>50%).

U.S. Pat. No. 6,545,088 B1 (Kolthammer et al.) discloses a process forpolymerizing ethylene, an alpha-olefin and optionally a diene catalyzedby a metallocene catalyst in either a single or multiple reactors.

U.S. Pat. No. 6,566,446 B1 (Kolthammer et al.) discloses a processcomprising interpolymerizing a first homogeneous ethylene/alpha-olefininterpolymer and at least one second homogeneous ethylene/alpha-olefininterpolymer using at least two constrained geometry catalysts. Thecatalysts have different reactivities such that the first interpolymerhas a narrow molecular weight distribution and a very high comonomercontent and relatively high molecular weight, and the secondethylene/alpha olefin interpolymer has a narrow molecular weightdistribution and a low comonomer content and a molecular weight lowerthan that of the first interpolymer. The interpolymers can bepolymerized in a single reactor or separate reactors operated inparallel of series.

WO 97/48735 (Canich et al.) discloses a mixed transition metal olefinpolymerization catalyst system comprising one late transition metalcatalyst and at least one different catalyst system selected from thegroup consisting of late transition metal catalyst systems, transitionmetal metallocene catalyst systems or Ziegler-Natta catalyst systems.

U.S. Pat. No. 4,939,217 (Stricklen) discloses a process for producing apolyolefin having a multimodal molecular weight distribution wherein thepolymerization is conducted in the presence of hydrogen and a catalystsystem containing alumoxane and at least two different metallocenes eachhaving different olefin polymerization termination rate constants.

U.S. Pat. No. 4,937,299 (Ewen et al.) discloses polyolefin reactorblends obtained by polymerization of ethylene and higher alpha-olefinsin the presence of a catalyst system comprising two or more metallocenesand alumoxane.

WO 02/074816A2 (deGroot et al.) discloses a polymer composition (andprocess for making) which comprises: (a) a high molecular weight,branched component; and (b) a low molecular weight, branched component.

WO 02/074817A2 (Stevens et al.) discloses a polymerization process whichcomprises contacting one or more olefinic comonomers in the presence ofat least a high molecular weight catalyst and at least a low molecularweight catalyst in a single reactor; and effectuating the polymerizationof the olefinic comonomers in the reactor to obtain an olefin polymer,whereby both catalysts have the ability to incorporate a substantiallysimilar amount of comonomers in the olefin polymer.

Such flexibility in polymer preparation is highly desirable in certainapplications, which call for a special and unique combination of polymerproperties. One such example is a polymer formulation employed in hotmelt adhesive (“HMA”) formulations. Most hot melt adhesives are threecomponent mixtures of a polymeric resin, a wax, and a tackifying agent.Although each component is generally present in roughly equalproportions in an HMA formulation, their relative ratio is often “finetuned” for a particular application's need. Typically, the polymercomponent provides the strength to the adhesive bond, while the waxreduces the overall viscosity of the system simplifying application ofthe adhesive to the substrate to be bonded.

The polymeric resin of an HMA can be ethylene homopolymers andinterpolymers of a selected molecular weight and density. Suchinterpolymers can be a single polymer or a blend composition. Forinstance, U.S. Pat. No. 5,530,054, issued Jun. 25, 1996 to Tse et al.,claims a hot melt adhesive composition consisting essentially of: (a) 30percent to 70 percent by weight of a copolymer of ethylene and about 6percent to about 30 percent by weight of a C₃ to C₂₀ α-olefin producedin the presence of a catalyst composition comprising a metallocene andan alumoxane and having an M_(W) of from about 20,000 to about 100,000;and (b) a hydrocarbon tackifier which is selected from a recited list.

U.S. Pat. No. 5,548,014, issued Aug. 20, 1996 to Tse et al., claims ahot melt adhesive composition comprising a blend ofethylene/alpha-olefin copolymers wherein the first copolymer has a M_(W)from about 20,000 to about 39,000 and the second copolymer has a M_(W)from about 40,000 to about 100,000. Each of the hot melt adhesivesexemplified comprises a blend of copolymers, with at least one of thecopolymers having a polydispersity greater than 2.5. Furthermore, thelowest density copolymer exemplified has a specific gravity of 0.894g/cm³.

However, it would be highly advantageous in such HMA applications tohave access to a synthetic polymer with properties such that it cansubstitute for both the wax and polymer components of a hot meltadhesive formulation.

It would also be highly advantageous to have a process for preparingsuch polymer composition comprising a minimum of mixing steps, thusmining the cost and variability of the formulation.

It would also be highly advantageous to have a polymer composition foruse in an HMA formulation, and a process for its preparation whichnegates the requirement of incorporating expensive petroleum waxes intohot melt adhesive formulations that are primarily imported and orderived from imported oil based feedstocks.

Finally, it would also be highly advantageous to have access to asynthetic polymer: i) with properties such that it can substitute forboth the wax and polymer components of a hot melt adhesive formulation;ii) which can be prepared by a process comprising a minimum of mixingsteps, thus minimizing the cost and variability of the formulation; iii)which when incorporated into a hot melt adhesive formulation, negatesthe need for expensive petroleum waxes (primarily imported and orderived from imported oil based feedstocks) in hot melt adhesiveformulations; and iv) which when incorporated into HMA formulations,said formulations are able to exhibit the strength and adhesioncharacteristics of commercial HMAs, while also exhibiting improvedthermal and oxidative stability.

SUMMARY OF THE INVENTION

The present invention is an ethylene alpha olefin interpolymer having adensity of from about 0.88 to about 1.06 g/cm³, preferably from about0.88 to about 0.93 g/cm³, more preferably from about 0.89 to about 0.92g/cm³, and even more preferably from about 0.895 to about 0.915 g/cm³.When the ethylene alpha olefin interpolymer comprises styrene comonomer,the density suitably ranges from about 0.931 to about 1.06 g/cm³,preferably from about 0.931 to about 1.03 g/cm³, and also preferablyfrom about 0.931 to about 0.96 g/cm³.

The ethylene alpha olefin interpolymer of the present invention has anumber average molecular weight (Mn as measured by GPC) of from about1,000, preferably from about 1,250, more preferably about 1,500 and evenmore preferably from about 2,000 up to about 9,000, preferably up toabout 7,000, and more preferably up to about 6,000.

The ethylene alpha olefin interpolymer of the present invention has aBrookfield Viscosity (measured at 300° F./149° C.) of from about 500,preferably about 1,000, and more preferably from about 1,500 up to about7,000 cP, preferably to about 6,000 cP, more preferably up to about5,000 cP.

The ethylene alpha olefin interpolymer of the present invention whenmixed with a tackifier results in an adhesive composition having aBrookfield Viscosity (measured at 350° F./177° C.) of from about 400,preferably about 500 and more preferably from about 750 up to about2,000 cP, preferably to about 1,400 cP, more preferably up to about1,200 cP.

The ethylene alpha olefin interpolymer of the present invention whenmixed with a tackifier results in an adhesive composition having a PeelAdhesion Failure Temperature (PAFT) of greater than or equal to 110° F.(43.3° C.), preferably greater than or equal to 115° F. (46.1° C.), morepreferably greater than or equal to 120° F. (48.8° C.).

The ethylene alpha olefin interpolymer of the present invention whenmixed with a tackifier results in an adhesive composition having a ShearAdhesion Failure Temperature (SAFT) of greater than or equal to 140° F.(60° C.), greater than or equal to 150° F. (65.5° C.), more preferablygreater than or equal to 170° F. (76.7° C.).

The ethylene alpha olefin interpolymer of the present invention whenmixed with a tackifier results in an adhesive composition which exhibits100% paper tear from 77 to 140° F. (25° to 60° C.), preferably 100%paper tear from 35 to 140° F. (1.70 to 60° C.), and most preferably 100%paper tear from 0 to 140° F. (negative 17.7° C. to 60° C.).

The resulting adhesive compositions noted above, suitably serve as hotmelt adhesives when appropriately formulated, for various endapplications in which such HMAs typically are employed.

Another embodiment of the invention provides a process of making anethylene alpha olefin interpolymer, comprising (a) contacting one ormore olefinic monomers in the presence of at least two catalysts; and(b) effectuating the polymerization of the olefinic monomers in one ormore reactors to obtain an olefin polymer, wherein each catalyst has theability to incorporate a different amount of comonomer in the polymer,and/or wherein each catalyst is capable of producing a polymer withsubstantially different molecular weights from the monomers underselected polymerization conditions.

In the processes of the present invention, one catalyst produces apolymer that has a molecular weight M_(wH) and the second catalystproduces a polymer with a molecular weight M_(wL). The process involvesproducing a C₂₋₂₀ olefin homopolymer or interpolymer, comprising (a)providing controlled addition of a first catalyst to a reactor, (b)providing controlled addition of a second catalyst to the reactor, eachcatalysts having different comonomer incorporation ability, (c)continuously feeding one or more C₂₋₂₀ olefins into a reactor, (d)continuously feeding each catalyst into a reactor at a rate sufficientto produce a polymer, wherein i) the ratio of the molecular weight (Mwas measured by GPC) of the polymer produced by one catalyst to themolecular weight of the polymer produced by the other catalyst,M_(wH)/M_(wL) is from about 1, preferably about 1.5, more preferablyfrom about 2 and up to about 20, preferably up to about 15, morepreferably up to about 10; and/or ii) the reactivity towards comonomerof each catalyst, as described by the ratio, r₁ ^(H)/r₁ ^(L), shouldfall between about 0.03, preferably between about 0.05 and morepreferably between about 0.1 and about 30, preferably about 20, and morepreferably about 10.

In some embodiments of the process, the polymerization is conducted in asingle reactor. In other embodiments, the polymerization is conducted intwo or more reactors wherein the first reactor is connected to thesecond reactor in parallel so that the mixing occurs in a third reactor.In another embodiment, the first reactor is connected to the secondreactor in series, while in others the first-reactor contents aresequentially introduced into the second reactor.

In some embodiments, such processes are performed under continuoussolution polymerization conditions. In some embodiments, the secondreactor is operated under continuous solution polymerization conditions.In some embodiments, ethylene has a steady state concentration of about3.5% or less by weight of the first-reactor contents, about 2.5% or lessby weight of the reactor content, or about 2.0% or less by weight of thefirst-reactor contents. In certain processes, the first reactor has apolymer with a steady state concentration of about 10% or more by weightof the first-reactor contents, about 18% or more by weight of thereactor content, or about 20% or more by weight of the reactor content.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an ethylene alpha olefin interpolymerwith desired processability and physical characteristics. The presentinvention also provides a new process for making the interpolymer,comprising contacting one or more olefinic monomers or comonomers in thepresence two or more single site catalysts (when employing a singlereactor) or one or more single site catalysts (when employing a multiplereactor process); and effectuating the polymerization of the olefiniccomonomers in said reactor(s) to obtain an olefin polymer. Preferably,the catalysts have the ability to incorporate a substantially differentamount of comonomer in the polymer produced, and/or produce a polymer ofsubstantially different molecular weight under selected polymerizationconditions.

In the following description, all numbers disclosed are approximatevalues, regardless whether the word “about” or “approximately” is usedin connection therewith. They may vary by up to 1%, 2%, 5%, or sometimes10 to 20%. Whenever a numerical range with a lower limit, R_(L), and anupper limit R_(U), is disclosed, any number R falling within the rangeis specifically disclosed. In particular, the following numbers R withinthe range are specifically disclosed: R=R_(L)+k*(R_(U)−R_(L)), wherein kis a variable ranging from 1% to 100% with a 1% increment, i.e. k is 1%,2%, 3%, 4%, 5%, . . . 50%, 51%, 52%, . . . , 95%, 96%, 97%, 98%, 99%, or100%. Moreover, for any numerical range defined by two numbers then R,as defined in the text above, is also specifically disclosed.

The term “polymer” as used herein refers to a macromolecular compoundprepared by polymerizing monomers of the same or a different type. Apolymer refers to homopolymers, copolymers, terpolymers, interpolymers,and so on.

The term “interpolymer” used herein refers to a polymer prepared by thepolymerization of at least two types of monomers or comonomers. Itincludes, but is not limited to, copolymers (which usually refers topolymers prepared from two different monomers or comonomers),terpolymers (which usually refers to polymers prepared from threedifferent types of monomers or comonomers), and tetrapolymers (whichusually refers to polymers prepared from four different types ofmonomers or comonomers), and the like.

The term “narrow composition distribution” used herein describes thecomonomer distribution for homogeneous interpolymers. The narrowcomposition distribution homogeneous interpolymers can also becharacterized by their SCBDI (short chain branch distribution index) orCDBI (composition distribution branch index). The SCBDI or CBDI isdefined as the weight percent of the polymer molecules having acomonomer content within 50 percent of the median total molar comonomercontent.

The CDBI of a polymer is readily calculated from data obtained fromtechniques known in the art, such as, for example, temperature risingelution fractionation (abbreviated herein as “TREF”) as described, forexample, in Wild et al, Journal Of Polymer Science, Poly. Phys. Ed.,Vol. 20, p. 441 (1982), or in U.S. Pat. No. 5,548,014, the disclosure ofwhich are incorporated herein by reference. Thus, the followingprocedure for calculating CDBI can be used:

-   -   (1) Generate a normalized, cumulative distribution plot of        copolymer concentration versus elution temperature, obtained        from the TREF.    -   (2) Determine the elution temperature at which 50 weight percent        of the dissolved copolymer has eluted.    -   (3) Determine the molar comonomer content within the copolymer        fraction eluting at that median elution temperature.    -   (4) Calculate limiting mole fraction values of 0.5 times and 1.5        times the molar comonomer content within the copolymer fraction        eluting at that median temperature.    -   (5) Determine limiting elution temperature values associated        with those limiting mole fraction values.    -   (6) Partially integrate that portion of the cumulative elution        temperature distribution between those limiting elution        temperature values.    -   (7) Express the result of that partial integration, CDBI, as a        percentage of the original, normalized, cumulative distribution        plot.

The term “different catalyst systems” is used herein in reference tocatalyst systems, which incorporate monomers at different amounts duringinterpolymerization. While the term principally refers to catalystsystems having different chemical compositions relative to one another,the term generally refers to any difference that results in differentmonomer incorporation or different polymerization reactivities or rates.As such, the term also refers to differences in concentrations,operating conditions, injection methods or timing and the like where thecatalyst systems have the same chemical composition.

One factor that influences the overall MWD is the difference between themolecular weights of the HMW component and the LMW component. In someembodiments, the ratio of the molecular weights of the polymer producedby one catalyst to the molecular weight of the polymer produced by theother catalyst, M_(wH)/M_(wL) is from about 1 to about 20, preferablyfrom about 1.5 to about 15, more preferably from about 2 to about 10.

Another factor that can have a substantial effect on the overall MWD isthe “polymer split” of the composition. A “polymer split” is defined asthe weight fraction of the high molecular weight polymer component in apolymer composition. The relative fractions of the high and lowmolecular weight components are determined from the deconvoluted GPCpeak. The polymer composition of the present invention has a split ofabout 30% to about 70%, preferably of from about 40% to about 60%, morepreferably of from about 45% to about 55%.

In the process, a high molecular weight catalyst is defined relative toa low molecular weight catalyst. A high weight molecular weight catalystrefers to a catalyst which produces a polymer with a high weight-averagemolecular weight M_(wH) from the monomers and any comonomers of choiceunder a set of given polymerization conditions, whereas a low molecularweight catalyst refers to a catalyst which produces a polymer with a lowweight average molecular weight M_(wL) from the same monomers andcomonomers under substantially the same polymerization conditions.Therefore, the terms “low molecular weight catalyst” and “high molecularweight catalyst” used herein do not refer to the molecular weight of acatalyst; rather, they refer to a catalyst's ability to make a polymerwith a low or high molecular weight. The intrinsic molecular weightdifferences in the polymer produced by the chosen high and low molecularweight catalysts produces the “polymer split” of the composition.

Thus, a high molecular weight catalyst and a low molecular weightcatalyst are determined with reference to each other. One does not knowwhether a catalyst is a high molecular weight catalyst or a lowmolecular weight catalyst until after another catalyst is also selected.Therefore, the terms “high molecular weight” and “low molecular weight”used herein when referring to a catalyst are merely relative terms anddo not encompass any absolute value with respect to the molecular weightof a polymer. After a pair of catalysts are selected, one can easilyascertain the high molecular weight catalyst by the followingprocedure: 1) select at least one monomer which can be polymerized bythe chosen catalysts; 2) make a polymer from the selected monomer(s) ina single reactor containing one of the selected catalysts underpre-selected polymerization conditions; 3) make another polymer from thesame monomer(s) in a single reactor containing the other catalyst undersubstantially the same polymerization conditions; and 4) measure themolecular weight of the respective interpolymers. The catalyst thatyields a higher Mw is the higher molecular weight catalyst. Conversely,the catalyst that yields a lower Mw is the lower molecular weightcatalyst. Using this methodology, it is possible to rank a plurality ofcatalysts based on the molecular weight of the polymers they can produceunder substantially the same conditions. As such, one may select three,four, five, six, or more catalysts according their molecular weightcapability and use these catalysts simultaneously in a singlepolymerization reactor to produce polymers with tailored structures andproperties.

Comonomer incorporation can be measured by many techniques that areknown in the art. One technique which may be employed is ¹³C NMRspectroscopy, an example of which is described for the determination ofcomonomer content for ethylene/alpha-olefin copolymers in Randall(Journal of Macromolecular Science, Reviews in Macromolecular Chemistryand Physics, C29 (2 & 3), 201-317 (1989)), the disclosure of which isincorporated herein by reference. The basic procedure for determiningthe comonomer content of an olefin interpolymer involves obtaining the¹³C NMR spectrum under conditions where the intensity of the peakscorresponding to the different carbons in the sample is directlyproportional to the total number of contributing nuclei in the sample.Methods for ensuring this proportionality are known in the art andinvolve allowance for sufficient time for relaxation after a pulse, theuse of gated-decoupling techniques, relaxation agents, and the like. Therelative intensity of a peak or group of peaks is obtained in practicefrom its computer-generated integral. After obtaining the spectrum andintegrating the peaks, those peaks associated with the comonomer areassigned. This assignment can be made by reference to known spectra orliterature, or by synthesis and analysis of model compounds, or by theuse of isotopically labeled comonomer. The mole % comonomer can bedetermined by the ratio of the integrals corresponding to the number ofmoles of comonomer to the integrals corresponding to the number of molesof all of the monomers in the interpolymer, as described in Randall, forexample.

The reactivity ratios of single site catalysts in general are obtainedby known methods, for example, as described in “Linear Method forDetermining Monomer Reactivity Ratios in Copolymerization”, M. Finemanand S. D. Ross, J. Polymer Science 5, 259 (1950) or “Copolymerization”,F. R. Mayo and C. Walling, Chem. Rev. 46, 191 (1950) incorporated hereinin their entirety by reference. For example, to determine reactivityratios the most widely used copolymerization model is based on thefollowing equations:

$\begin{matrix}{M_{1}^{*} + {M_{1}\overset{K_{11}}{\longrightarrow}M_{1}^{*}}} & (1) \\{M_{1}^{*} + {M_{2}\overset{K_{12}}{\longrightarrow}M_{2}^{*}}} & (2) \\{M_{2}^{*} + {M_{1}\overset{K_{21}}{\longrightarrow}M_{1}^{*}}} & (3) \\{M_{2}^{*} + {M_{2}\overset{K_{22}}{\longrightarrow}M_{2}^{*}}} & (4)\end{matrix}$where M_(i) refers to a monomer molecule which is arbitrarily designatedas “i” where i=1, 2; and M₂* refers to a growing polymer chain to whichmonomer i has most recently attached.

The k_(ij) values are the rate constants for the indicated reactions.For example, in ethylene/propylene copolymerization, k₁₁ represents therate at which an ethylene unit inserts into a growing polymer chain inwhich the previously inserted monomer unit was also ethylene. Thereactivity ratios follow as: r₁=k₁₁/k₁₂ and r₂=k₂₂/k₂₁ wherein k₁₁, k₁₂,k₂₂ and k₂₁ are the rate constants for ethylene (1) or propylene (2)addition to a catalyst site where the last polymerized monomer is anethylene (k_(1X)) or propylene (k_(2X)).

Because the change in r₁ with temperature may vary from catalyst tocatalyst, it should be appreciated that the term “different comonomerincorporation” refers to catalysts which are compared at the same orsubstantially the same polymerization conditions, especially with regardto polymerization temperature. Thus, a pair of catalysts may not possess“different comonomer incorporation” at a low polymerization temperature,but may possess “different comonomer incorporation” at a highertemperature, and visa versa. For the purposes of this invention,“different comonomer incorporation” refers to catalysts, which arecompared at the same or substantially the same polymerizationtemperature. Because it is also known that different cocatalysts oractivators can have an effect on the amount of comonomer incorporationin an olefin copolymerization, it should be appreciated that “differentcomonomer incorporation” refers to catalysts which are compared usingthe same or substantially the same cocatalyst(s) or activator(s). Thus,for the purposes of this invention, a test to determine whether or nottwo or more catalysts have “different comonomer incorporation” should beconducted with each catalyst using the same method of activation foreach catalyst, and the test should be conducted at the samepolymerization temperature, pressure, and monomer content (includingcomonomer concentration) as is used in the instant inventive processwhen the individual catalysts are used together.

When a low molecular weight catalyst with r₁ ^(L) and a high molecularweight catalyst with r₁ ^(H) are selected, the r₁ ratio, r₁ ^(H)/r₁^(L), is another way to define the amount of comonomer incorporation bythe low and high molecular weight catalysts. The ratio, r₁ ^(H)/r₁ ^(L),preferably falls between about 0.03 to about 30, more preferably betweenabout 0.05 to about 20, and most preferably between about 0.1 to about10. Conventional wisdom would cause some to surmise that an interpolymermade from catalysts pairs possessing a r₁ ^(H)/r₁ ^(L) ratio less thanunity might impart adhesive properties substantially better than aninterpolymer where that ratio is greater than 1. We have found thatexcellent adhesive performance can be obtained with interpolymers of theinvention that fall into either category. See performance data reportedin Table 5 for adhesive formulations made from the ten examples ofinterpolymers prepared as recorded in Table 3. That data suggests thatformulations based on Polymer numbers 1-4 and 8 made from catalyst pairshaving a r₁ ^(H)/r₁ ^(L) ratio of greater than unity, surprisinglyexhibit equally good adhesive properties when compared to formulationsbased on Polymer numbers 5-7, 9 and 10 which were made with catalystpairs having a r₁ ^(H)/r₁ ^(L) ratio less than unity.

Generally, a lower r₁ indicates a higher comonomer incorporation abilityfor the catalyst. Conversely, a higher r₁ generally indicates a lowercomonomer incorporation ability for the catalyst (i.e., a higherreactivity toward ethylene than comonomer and hence a tendency to makean ethylene homopolymer). Therefore, if one desires to make a copolymerwith a minimal density split, it would be preferable to use at least twocatalysts with substantially similar or identical r₁, on the other hand,when one desires to make a blend of homopolymers and copolymers with asignificant density split, it would be preferable to employ at least twocatalysts with substantially dissimilar r₁.

The high molecular weight catalysts and the low molecular weightcatalysts may be selected such that they have the ability to incorporatea different amount of comonomers in the polymer. In other words, undersubstantially the same conditions of temperature, pressure, and monomercontent (including comonomer concentration), each catalyst incorporatesa different mole percentage of comonomers into the resultinginterpolymer. One way to quantify “different” mole percentage ofcomonomers is as follows: where a difference between the comonomerincorporation of the first catalyst and second catalyst of at least a 10percent delta exists; e.g., for a first catalyst that incorporates 20mole % comonomer a second catalyst will incorporate 18 or less mole % or22 or greater mole % of the comonomer.

Preferably, for all of the ethylene homopolymers and inttrpolymersdescribed immediately above, at least two of the catalysts used in asingle reactor have different comonomer incorporation, and the processused is a gas phase, slurry, or solution process. More preferably, forall of the ethylene homopolymers and interpolymers described immediatelyabove, at least two of the catalysts used in a single reactor havedifferent comonomer incorporation, and M_(w) ^(H)/M_(w) ^(L) is fromabout 1 to about 20, preferably from about 1.5 to about 15, morepreferably from about 2 to about 10.

Preferably, the process used is a continuous solution process,especially a continuous solution process wherein the polymerconcentration in the reactor at steady state is at least 10% by weightof the reactor contents and the ethylene concentration is 3.5% or lessby weight of the reactor contents.

Still more preferably, the process used is a continuous solution processwherein the polymer concentration in the reactor at steady state is atleast 18% by weight of the reactor contents and the ethyleneconcentration is 2.5% or less by weight of the reactor contents.

Most preferably, for all of the ethylene homopolymers and interpolymersdescribed immediately above, at least two of the catalysts used in asingle reactor have a different comonomer incorporation, and the processused is a continuous solution process wherein the polymer concentrationin the reactor at steady state is at least 20% by weight of the reactorcontents and the ethylene concentration is 2.0% or less by weight of thereactor contents.

The catalysts used in the process of the present invention when usedindividually produce homogeneous ethylene/α-olefin interpolymers. Theterm “homogeneous interpolymer” is used herein to indicate a linear orsubstantially linear ethylene interpolymer prepared using a constrainedgeometry or single site metallocene catalyst. By the term homogeneous,it is meant that any comonomer is randomly distributed within a giveninterpolymer molecule and substantially all of the interpolymermolecules have the same ethylene/comonomer ratio within thatinterpolymer. The melting peak of homogeneous linear and substantiallylinear ethylene polymers, as determined by differential scanningcalorimetry (DSC), will broaden as the density decreases and/or as thenumber average molecular weight decreases.

The homogeneous linear or substantially linear ethylene polymers arecharacterized as having a narrow molecular weight distribution (Mw/Mn).For the linear and substantially linear ethylene polymers, the Mw/Mn ispreferably about 1.5 or greater, preferably about 1.8 or greater toabout 2.6 or less, preferably to about 2.4 or less.

Certain interpolymer compositions of the present invention when producedusing multiple single site catalysts may, depending upon the relativecontributions of each catalyst-derived product, exhibit much largervalues. In such case, the molecular weight distribution (Mw/Mn) valuesmay be from about 2 up to about 20, preferably up to about 15 and morepreferably up to about 12.

Homogeneously branched linear ethylene/α-olefin interpolymers may beprepared using polymerization processes (such as is described by Elstonin U.S. Pat. No. 3,645,992) which provide a homogeneous short chainbranching distribution. In his polymerization process, Elston usessoluble vanadium catalyst systems to make such polymers. However, otherssuch as Mitsui Petrochemical Company and Exxon Chemical Company haveused so-called single site metallocene catalyst systems to make polymershaving a homogeneous linear structure. Homogeneous linearethylene/α-olefin interpolymers are currently available from MitsuiPetrochemical Company under the tradename “TAFMER™” and from ExxonChemical Company under the tradename “EXACT™”.

Substantially linear ethylene polymers are homogeneous polymers havinglong chain branching. The long chain branches have the same comonomerdistribution as the polymer backbone and can be as long as about thesame length as the length of the polymer backbone. When a substantiallylinear ethylene polymer is employed in the practice of the invention,such polymer may be characterized as having a polymer backbonesubstituted with from 0.01 to 3 long chain branches per 1,000 carbons.

For quantitative methods for determination, see, for instance, U.S. Pat.Nos. 5,272,236 and 5,278,272; Randall (Rev. Macromol. Chem. Phys., C29(2 &3), p. 285-297), which discusses the measurement of long chainbranching using 13C nuclear magnetic resonance spectroscopy, Zimm, G. H.and Stockmayer, W. H., J. Chem. Phys., 17, 1301 (1949); and Rudin, A.,Modern Methods of Polymer Characterization, John Wiley & Sons, New York(1991) pp. 103-112, which discuss the use of gel permeationchromatography coupled with a low angle laser light scattering detector(GPC-LALLS) and gel permeation chromatography coupled with adifferential viscometer detector (GPC-DV).

Most preferred are interpolymers of ethylene with at least one C₃-C₃₀α-olefin, (for instance, propylene, 1-butene, 1-pentene, 1-hexene,4-methyl-1-pentene, and 1-octene), with interpolymers of ethylene withat least one C₄-C₂₀ α-olefin, particularly at least one C₆-C₁₀ α-olefin,being most preferred. Another preferred class of interpolymers ofethylene are those prepared with at least one comonomer being styrene.

Substantially linear ethylene/α-olefin interpolymers are available fromThe Dow Chemical Company as AFFINITY™ polyolefin plastomers.Substantially linear ethylene/alpha-olefin interpolymers may be preparedin accordance with the techniques described in U.S. Pat. No. 5,272,236and in U.S. Pat. No. 5,278,272, the entire contents of both of which areherein incorporated by reference.

The present invention is a polymer composition, derived from ethyleneand alpha olefin, which can be used as an alternative to conventionalhot melt adhesives that are subsequently used to bond articles, yetwhich composition yields adhesive properties similar to adhesivescontaining polymer, wax and tackifier.

The present invention has discovered that use of a specific type ofhomogeneous interpolymer can unexpectedly be used by itself or incombination with a tackifier to produce commercially acceptable hot meltadhesives. The present invention is a hot melt adhesive comprising aspecific synthetic interpolymer that, when combined with a suitabletackifier, can be used as an alternative to hot melt adhesiveformulations that incorporate a three-component wax, polymer andtackifier mixture.

The homogenous interpolymer of the present invention may be preparedusing a mixture of the constrained geometry catalysts. Such catalystsare disclosed in U.S. Pat. Nos. 5,064,802, 5,132,380, 5,703,187,6,034,021, EP 0 468 651, EP 0 514 828, WO 93/19104, and WO 95/00526, allof which are incorporated by references herein in their entirety.Another suitable class of catalysts is the metallocene catalystsdisclosed in U.S. Pat. Nos. 5,044,438; 5,057,475; 5,096,867; and5,324,800, all of which are incorporated by reference herein in theirentirety. It is noted that constrained geometry catalysts may beconsidered as metallocene catalysts, and both are sometimes referred toin the art as single-site catalysts.

For example, catalysts may be selected from the metal coordinationcomplexes corresponding to the formula:

wherein: M is a metal of group 3, 4-10, or the lanthanide series of theperiodic table of the elements; Cp* is a cyclopentadienyl or substitutedcyclopentadienyl group bound in an η⁵ bonding mode to M; Z is a moietycomprising boron, or a member of group 14 of the periodic table of theelements, and optionally sulfur or oxygen, the moiety having up to 40non-hydrogen atoms, and optionally Cp* and Z together form a fused ringsystem; X independently each occurrence is an anionic ligand group, saidX having up to 30 non-hydrogen atoms; n is 2 less than the valence of Mwhen Y is anionic, or 1 less than the valence of M when Y is neutral; Lindependently each occurrence is a neutral Lewis base ligand group, saidL having up to 30 non-hydrogen atoms; m is 0, 1, 2, 3, or 4; and Y is ananionic or neutral ligand group bonded to Z and M comprising nitrogen,phosphorus, oxygen or sulfur and having up to 40 non-hydrogen atoms,optionally Y and Z together form a fused ring system.

Suitable catalysts may also be selected from the metal coordinationcomplex corresponds to the formula:

wherein R′ each occurrence is independently selected from the groupconsisting of hydrogen, alkyl, aryl, silyl, germyl, cyano, halo andcombinations thereof having up to 20 non-hydrogen atoms; X eachoccurrence independently is selected from the group consisting ofhydride, halo, alkyl, aryl, silyl, germyl, aryloxy, alkoxy, amide,siloxy, and combinations thereof having up to 20 non-hydrogen atoms; Lindependently each occurrence is a neutral Lewis base ligand having upto 30 non-hydrogen atoms; Y is —O—, —S—, —NR*-, —PR*-, or a neutral twoelectron donor ligand selected from the group consisting of OR*, SR*,NR*2, PR*₂; M, n, and m are as previously defined; and Z is SIR*₂, CR*₂,SiR*₂SiR*₂, CR*₂CR*₂, CR*═CR*, CR*₂SiR*₂, GeR*₂, BR*, BR*₂; wherein: R*each occurrence is independently selected from the group consisting ofhydrogen, alkyl, aryl, silyl, halogenated alkyl, halogenated aryl groupshaving up to 20 non-hydrogen atoms, and mixtures thereof, or two or moreR* groups from Y, Z, or both Y and Z form a fused ring system.

It should be noted that whereas formula I and the following formulaeindicate a monomeric structure for the catalysts, the complex may existas a dimer or higher oligomer.

Further preferably, at least one of R′, Z, or R* is an electron donatingmoiety. Thus, highly preferably Y is a nitrogen or phosphorus containinggroup corresponding to the formula —N(R″″)— or —P(R″″)—, wherein R″″ isC₁₋₁₀ alkyl or aryl, i.e., an amido or phosphido group.

Additional catalysts may be selected from the amidosilane- oramidoalkanediyl-compounds corresponding to the formula:

wherein: M is titanium, zirconium or hafnium, bound in an η⁵ bondingmode to the cyclopentadienyl group; R′ each occurrence is independentlyselected from the group consisting of hydrogen, silyl, alkyl, aryl andcombinations thereof having up to 10 carbon or silicon atoms; E issilicon or carbon; X independently each occurrence is hydride, halo,alkyl, aryl, aryloxy or alkoxy of up to 10 carbons; m is 1 or 2; and nis 1 or 2 depending on the valence of M.

Examples of the above metal coordination compounds include, but are notlimited to, compounds in which the R′ on the amido group is methyl,ethyl, propyl, butyl, pentyl, hexyl, (including isomers), norbornyl,benzyl, phenyl, etc.; the cyclopentadienyl group is cyclopentadienyl,indenyl, tetrahydroindenyl, fluorenyl, octahydrofluorenyl, etc.; R′ onthe foregoing cyclopentadienyl groups each occurrence is hydrogen,methyl, ethyl, propyl, butyl, pentyl, hexyl, (including isomers),norbornyl, benzyl, phenyl, etc.; and X is chloro, bromo, iodo, methyl,ethyl, propyl, butyl, pentyl, hexyl, (including isomers), norbornyl,benzyl, phenyl, etc.

Specific compounds include, but are not limited to,(tertbutylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediylzirconiumdimethyl,(tert-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyltitaniumdimethyl,(methylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediylzirconiumdichloride,(methylamido)(tetramethyl-η⁵-eyelopentadienyl)-1,2-ethanediyltitaniumdichloride,(ethylamido)(tetramethyl-η⁵-cyclopentadienyl)methylenetitaniumdichloride,(tertbutylamido)diphenyl(tetramethyl-η⁵-cyclopentadienyl)silanezirconiumdibenzyl,(benzylamido)dimethyl(tetramethyl-η⁵-cyclopentadienyl)silanetitaniumdichloride,phenylphosphido)dimethyl(tetramethyl-η⁵-cyclopentadienyl)silanezirconiumdibenzyl, and the like.

Another suitable class of catalysts is substituted indenyl containingmetal complexes as disclosed in U.S. Pat. No. 5,965,756 and No.6,015,868, which are incorporated by reference in their entirety. Othercatalysts are disclosed in copending applications U.S. Pat. Nos.6,268,444; 6,515,155; 6,613,921 and WO 01/042315A1. The disclosures ofall of the preceding patent applications or publications areincorporated by reference in their entirety. These catalysts tend tohave a higher molecular weight capability.

One class of the above catalysts is the indenyl containing metalwherein:

M is titanium, zirconium or hafnium in the +2, +3 or +4 formal oxidationstate;

A′ is a substituted indenyl group substituted in at least the 2 or 3position with a group selected from hydrocarbyl, fluoro-substitutedhydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl,dialkylamino-substituted hydrocarbyl, silyl, germyl and mixturesthereof, the group containing up to 40 non-hydrogen atoms, and the A′further being covalently bonded to M by means of a divalent Z group; Zis a divalent moiety bound to both A′ and M via σ-bonds, the Zcomprising boron, or a member of Group 14 of the Periodic Table of theElements, and also comprising nitrogen, phosphorus, sulfur or oxygen; Xis an anionic or dianionic ligand group having up to 60 atoms exclusiveof the class of ligands that are cyclic, delocalized, π-bound ligandgroups; X′ independently each occurrence is a neutral Lewis base, havingup to 20 atoms; p is 0, 1 or 2, and is two less than the formaloxidation state of M, with the proviso that when X is a dianionic ligandgroup, p is 1; and q is 0, 1 or 2.

The above complexes may exist as isolated crystals optionally in pureform or as a mixture with other complexes, in the form of a solvatedadduct, optionally in a solvent, especially an organic liquid, as wellas in the form of a dimer or chelated derivative thereof, wherein thechelating agent is an organic material, preferably a neutral Lewis base,especially a trihydrocarbylamine, trihydrocarbylphosphine, orhalogenated derivative thereof.

Other preferred catalysts are complexes corresponding to the formula:

wherein R₁ and R₂ independently are groups selected from hydrogen,hydrocarbyl, perfluoro substituted hydrocarbyl, silyl, germyl andmixtures thereof, the group containing up to 20 non-hydrogen atoms, withthe proviso that at least one of R₁ or R₂ is not hydrogen; R₃, R₄, R₅,and R₆ independently are groups selected from hydrogen, hydrocarbyl,perfluoro substituted hydrocarbyl, silyl, germyl and mixtures thereof,the group containing up to 20 non-hydrogen atoms; M is titanium,zirconium or hafnium; Z is a divalent moiety comprising boron, or amember of Group 14 of the Periodic Table of the Elements, and alsocomprising nitrogen, phosphorus, sulfur or oxygen, the moiety having upto 60 non-hydrogen atoms; p is 0, 1 or 2; q is zero or one; with theproviso that: when p is 2, q is zero, M is in the +4 formal oxidationstate, and X is an anionic ligand selected from the group consisting ofhalide, hydrocarbyl, hydrocarbyloxy, di(hydrocarbyl)amido,di(hydrocarbyl)phosphido, hydrocarbyl sulfido, and silyl groups, as wellas halo-, di(hydrocarbyl)amino-, hydrocarbyloxy- anddi(hydrocarbyl)phosphino-substituted derivatives thereof, the X grouphaving up to 20 non-hydrogen atoms, when p is 1, q is zero, M is in the+3 formal oxidation state, and X is a stabilizing anionic ligand groupselected from the group consisting of allyl,2-(N,N-dimethylaminomethyl)phenyl, and 2-(N,N-dimethyl)-aminobenzyl, orM is in the +4 formal oxidation state, and X is a divalent derivative ofa conjugated diene, M and X together forming a metallocyclopentenegroup, and when p is 0, q is 1, M is in the +2 formal oxidation state,and X′ is a neutral, conjugated or non-conjugated diene, optionallysubstituted with one or more hydrocarbyl groups, the X′ having up to 40carbon atoms and forming a π-complex with M.

More preferred catalysts are complexes corresponding to the formula:

wherein: R₁ and R₂ are hydrogen or C₁₋₆ alkyl, with the proviso that atleast one of R₁ or R₂ is not hydrogen; R₃, R₄, R₅, and R₆ independentlyare hydrogen or C₁₋₆ alkyl; M is titanium; Y is —O—, —NR*-, —PR*-; Z* isSiR*₂, CR*₂, SiR*₂SiR*₂, CR*₂CR*₂, CR*═CR*, CR*₂SiR*₂, or GeR*₂; R* eachoccurrence is independently hydrogen, or a member selected fromhydrocarbyl, hydrocarbyloxy, silyl, halogenated alkyl, halogenated aryl,and combinations thereof, the R* having up to 20 non-hydrogen atoms, andoptionally, two R* groups from Z (when R* is not hydrogen), or an R*group from Z and an R* group from Y form a ring system; p is 0, 1 or 2;q is zero or one; with the proviso that: when p is 2, q is zero, M is inthe +4 formal oxidation state, and X is independently each occurrencemethyl or benzyl, when p is 1, q is zero, M is in the +3 formaloxidation state, and X is 2-(N,N-dimethyl)aminobenzyl; or M is in the +4formal oxidation state and X is 1,4-butadienyl, and when p is 0, q is 1,M is in the +2 formal oxidation state, and X′ is1,4-diphenyl-1,3-butadiene or 1,3-pentadiene. The latter diene isillustrative of unsymmetrical diene groups that result in production ofmetal complexes that are actually mixtures of the respective geometricalisomers.

Other catalysts, cocatalysts, catalyst systems, and activatingtechniques which may be used in the practice of the invention disclosedherein may include those disclosed in; U.S. Pat. No. 5,616,664, WO96/23010, published on Aug. 1, 1996, WO 99/14250, published Mar. 25,1999, WO 98/41529, published Sep. 24, 1998, WO 97/42241, published Nov.13, 1997, WO 97/42241, published Nov. 13, 1997, those disclosed byScollard, et al., in J. Am. Chem. Soc 1996, 118, 10008-10009, EP 0 468537 B1, published Nov. 13, 1996, WO 97/22635, published Jun. 26, 1997,EP 0 949 278 A2, published Oct. 13, 1999; EP 0 949 279 A2, publishedOct. 13, 1999; EP 1 063 244 A2, published Dec. 27, 2000; U.S. Pat. Nos.5,408,017; 5,767,208; 5,907,021; WO 88/05792, published Aug. 11, 1988;WO88/05793, published Aug. 11, 1988; WO 93/25590, published Dec. 23,1993;U.S. Pat. Nos. 5,599,761; 5,218,071; WO 90/07526, published Jul.12, 1990; U.S. Pat. Nos. 5,972,822; 6,074,977; 6,013,819; 5,296,433;4,874,880; 5,198,401; 5,621,127; 5,703,257; 5,728,855; 5,731,253;5,710,224; 5,883,204; 5,504,049; 5,962,714; 6,150,297, 5,965,677;5,427,991; WO 93/21238, published Oct. 28, 1993; WO 94/03506, publishedFeb. 17, 1994; WO 93/21242, published Oct. 28, 1993; WO 94/00500,published Jan. 6, 1994, WO 96/00244, published Jan. 4, 1996, WO98/50392, published Nov. 12, 1998; Wang, et al., Organometallics 1998,17, 3149-3151; Younkin, et al., Science 2000, 287, 460-462, Chen andMarks, Chem. Rev. 2000, 100, 1391-1434, Alt and Koppl, Chem. Rev. 2000,100, 1205-1221; Resconi, et al., Chem. Rev. 2000, 100, 1253-1345; Ittel,et al., ChemRev. 2000, 100, 1169-1203; Coates, Chem. Rev., 2000, 100,1223-1251; WO 96/13530, published May 9, 1996; all of which patents andpublications are herein incorporated by reference in their entirety.Also useful are those catalysts, cocatalysts, and catalyst systemsdisclosed in U.S. Pat. No. 5,965,756; No. 6,150,297; and publicationsU.S. Pat. Nos. 6,268,444 and 6,515,155; all of which patents andpublications are incorporated by reference in their entirety. Inaddition, methods for preparing the aforementioned catalysts aredescribed, for example, in U.S. Pat. No. 6,015,868, the entire contentof which is incorporated by reference.

Cocatalysts:

The above-described catalysts may be rendered catalytically active bycombination with an activating cocatalyst or by use of an activatingtechnique. Suitable activating cocatalysts for use herein include, butare not limited to, polymeric or oligomeric alumoxanes, especiallymethylalumoxane, triisobutylaluminum modified methylalumoxane, orisobutylalumoxane; neutral Lewis acids, such as C₁₋₃₀ hydrocarbylsubstituted Group 13 compounds, especially tri(hydrocarbyl)aluminum ortri(hydrocarbyl)boron compounds and halogenated (includingperhalogenated) derivatives thereof, having from 1 to 30 carbons in eachhydrocarbyl or halogenated hydrocarbyl group, more especiallyperfluorinated tri(aryl)boron and perfluorinated tri(aryl)aluminumcompounds, mixtures of fluoro-substituted(aryl)boron compounds withalkyl-containing aluminum compounds, especially mixtures oftris(pentafluorophenyl)borane with trialkylaluminum or mixtures oftris(pentafluorophenyl)borane with alkylalumoxanes, more especiallymixtures of tris(pentafluorophenyl)borane with methylalumoxane andmixtures of tris(pentafluorophenyl)borane with methylalumoxane modifiedwith a percentage of higher alkyl groups (MMAO), and most especiallytris(pentafluorophenyl)borane and tris(pentafluorophenyl)aluminum;non-polymeric, compatible, non-coordinating, ion forming compounds(including the use of such compounds under oxidizing conditions),especially the use of ammonium-, phosphonium-, oxonium-, carbonium-,silylium- or sulfonium-salts of compatible, non-coordinating anions, orferrocenium salts of compatible, non-coordinating anions; bulkelectrolysis and combinations of the foregoing activating cocatalystsand techniques. The foregoing activating cocatalysts and activatingtechniques have been previously taught with respect to different metalcomplexes in the following references: EP-A-277,003, U.S. Pat. Nos.5,153,157, 5,064,802, EP-A468,651 (equivalent to U.S. Ser. No.07/547,718), EP-A-520,732 (equivalent to U.S. Ser. No. 07/876,268), andEP-A-520,732 (equivalent to U.S. Ser. No. 07/884,966 filed May 1, 1992).The disclosures of the all of the preceding patents or patentapplications are incorporated by reference in their entirety.

Combinations of neutral Lewis acids, especially the combination of atrialkyl aluminum compound having from 1 to 4 carbons in each alkylgroup and a halogenated tri(hydrocarbyl)boron compound having from 1 to20 carbons in each hydrocarbyl group, especiallytris(pentafluorophenyl)borane, further combinations of such neutralLewis acid mixtures with a polymeric or oligomeric alumoxane, andcombinations of a single neutral Lewis acid, especiallytris(pentafluorophenyl)borane with a polymeric or oligomeric alumoxaneare especially desirable activating cocatalysts. It has been observedthat the most efficient catalyst activation using such a combination oftris(pentafluoro-phenyl)borane/alumoxane mixture occurs at reducedlevels of alumoxane. Preferred molar ratios of Group 4 metalcomplex:tris(pentafluoro-phenylborane:alumoxane are from 1:1:1 to1:5:10, more preferably from 1:1:1 to 1:3:5. Such efficient use of lowerlevels of alumoxane allows for the production of olefin polymers withhigh catalytic efficiencies using less of the expensive alumoxanecocatalyst. Additionally, polymers with lower levels of aluminumresidue, and hence greater clarity, are obtained.

Suitable ion forming compounds useful as cocatalysts in some embodimentsof the invention comprise a cation which is a Br{acute over (ø)}nstedacid capable of donating a proton, and a compatible, non-coordinatinganion, A⁻. As used herein, the term “non-coordinating” means an anion orsubstance which either does not coordinate to the Group 4 metalcontaining precursor complex and the catalytic derivative derivedtherefrom, or which is only weakly coordinated to such complexes therebyremaining sufficiently labile to be displaced by a neutral Lewis base. Anon-coordinating anion specifically refers to an anion which, whenfunctioning as a charge balancing anion in a cationic metal complex,does not transfer an anionic substituent or fragment thereof to thecation thereby forming neutral complexes during the time which wouldsubstantially interfere with the intended use of the cationic metalcomplex as a catalyst. “Compatible anions” are anions which are notdegraded to neutrality when the initially formed complex decomposes andare non-interfering with desired subsequent polymerization or other usesof the complex.

Preferred anions are those containing a single coordination complexcomprising a charge-bearing metal or metalloid core which anion iscapable of balancing the charge of the active catalyst species (themetal cation) which may be formed when the two components are combined.Also, the anion should be sufficiently labile to be displaced byolefinic, diolefinic and acetylenically unsaturated compounds or otherneutral Lewis bases such as ethers or nitriles. Suitable metals include,but are not limited to, aluminum, gold and platinum. Suitable metalloidsinclude, but are not limited to, boron, phosphorus, and silicon.Compounds containing anions which comprise coordination complexescontaining a single metal or metalloid atom are, of course, known in theart and many, particularly such compounds containing a single boron atomin the anion portion, are available commercially.

Preferably such cocatalysts may be represented by the following generalformula:(L*-H)_(d) ⁺(A)^(d−)  Formula VIIwherein L* is a neutral Lewis base; (L*-H)+ is a Bronsted acid; A^(d−)is an anion having a charge of d−, and d is an integer from 1 to 3. Morepreferably A^(d−) corresponds to the formula: [M′Q₄]⁻; wherein M′ isboron or aluminum in the +3 formal oxidation state; and Q independentlyeach occurrence is selected from hydride, dialkylamido, halide,hydrocarbyl, hydrocarbyloxy, halosubstituted-hydrocarbyl,halosubstituted hydrocarbyloxy, and halo-substituted silylhydrocarbylradicals (including perhalogenated hydrocarbyl-, perhalogenatedhydrocarbyloxy- and perhalogenated silylhydrocarbyl radicals), the Qhaving up to 20 carbons with the proviso that in not more than oneoccurrence is Q halide. Examples of suitable hydrocarbyloxy Q groups aredisclosed in U.S. Pat. No. 5,296,433.

In a more preferred embodiment, d is one, that is, the counter ion has asingle negative charge and is A⁻. Activating cocatalysts comprisingboron which are particularly useful in the preparation of catalysts ofthis invention may be represented by the following general formula:(L*-H)⁺(M′Q₄)⁻;  Formula VIIIwherein L* is as previously defined; M′ is boron or aluminum in a formaloxidation state of 3; and Q is a hydrocarbyl-, hydrocarbyloxy-,fluorinated hydrocarbyl-, fluorinated hydrocarbyloxy-, or fluorinatedsilylhydrocarbyl-group of up to 20 non-hydrogen atoms, with the provisothat in not more than one occasion is Q hydrocarbyl. Most preferably, Qin each occurrence is a fluorinated aryl group, especially apentafluorophenyl group. Preferred (L*-H)⁺ cations areN,N-dimethylanilinium, N,N-di(octadecyl)anilinium,di(octadecyl)methylammonium, methylbis(hydrogenated tallowyl)ammonium,and tributylammonium.

Illustrative, but not limiting, examples of boron compounds which may beused as an activating cocatalyst are tri-substituted ammonium salts suchas: trimethylammonium tetrakis(pentafluorophenyl) borate;triethylammonium tetrakis(pentafluorophenyl)borate; tripropylammoniumtetrakis(pentafluorophenyl)borate; tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)borate; tri(sec-butyl)ammoniumtetrakis(pentafluorophenyl)-borate; N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate; N,N-dimethylaniliniumn-butyltris(pentafluorophenyl)borate; N,N-dimethylaniliniumbenzyltris(pentafluorophenyl)borate; N,N-dimethylaniliniumtetrakis(4-(t-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl)borate;N,N-dimethylaniliniumtetrakis(4-(triisopropylsilyl)-2,3,5,6-tetrafluorophenyl)borate;N,N-dimethylanilinium pentafluorophenoxytris(pentafluorophenyl)borate;N,N-diethylanilinium tetrakis(pentafluorophenyl)borate;N,N-dimethyl-2,4,6-trimethylanilinium tetrakis(pentafluorophenyl)borate;trimethylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate;triethylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate;tripropylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate;tri(n-butyl)ammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate;dimethyl(t-butyl)ammonium tetrakis(2,3,4,6-tetra fluorophenyl)borate;N,N-dimethylanilinium tetrakis(2,3,4,6-tetrafluorophenyl)-borate;N,N-diethylanilinium tetrakis(2,3,4,6-tetrafluorophenyl)borate; andN,N-dimethyl-2,4,6-trimethylaniliniumtetrakis(2,3,4,6-tetrafluorophenyl)borate; dialkyl ammonium salts suchas: di-(i-propyl)ammonium tetrakis(pentafluorophenyl)borate; anddicyclohexylammonium tetrakis(pentafluorophenyl)borate; tri-substitutedphosphonium salts such as: triphenylphosphoniumtetrakis(pentafluorophenyl)borate; tri(o-tolyl)phosphoniumtetrakis(pentafluorophenyl)borate; andtri(2,6-dimethylphenyl)-phosphonium tetrakis(pentafluorophenyl)borate;di-substituted oxonium salts such as: diphenyloxoniumtetrakis(pentafluorophenyl)borate; di(o-tolyl)oxonium tetrakis(pentafluorophenyl)borate; and di(2,6-dimethylphenyl)oxoniumtetrakis(pentafluorophenyl)borate; di-substituted sulfonium salts suchas: diphenylsulfonium tetrakis(pentafluorophenyl)borate;di(o-tolyl)sulfonium tetrakis(pentafluorophenyl)borate; andbis(2,6-dimethylphenyl) sulfonium tetrakis(pentafluorophenyl)borate.

Preferred silylium salt activating cocatalysts include, but are notlimited to, trimethylsilylium tetrakispentafluorophenylborate,triethylsilylium tetrakispentafluoro-phenylborate and ether substitutedadducts thereof. Silylium salts have been previously genericallydisclosed in J. Chem. Soc. Chem. Comm., 1993, 383-384, as well asLambert, J. B., et al., Organometallics, 1994, 13, 2430-2443. The use ofthe above silylium salts as activating cocatalysts for additionpolymerization catalysts is disclosed in U.S. Pat. No. 5,625,087, whichis incorporated by reference herein in its entirety. Certain complexesof alcohols, mercaptans, silanols, and oximes withtris(pentafluorophenyl)borane are also effective catalyst activators andmay be used in embodiments of the invention. Such cocatalysts aredisclosed in U.S. Pat. No. 5,296,433, which is also incorporated byreference in its entirety.

The catalyst system may be prepared as a homogeneous catalyst byaddition of the requisite components to a solvent in whichpolymerization will be carried out by solution polymerizationprocedures. The catalyst system may also be prepared and employed as aheterogeneous catalyst by adsorbing the requisite components on acatalyst support material such as silica gel, alumina or other suitableinorganic support material. When prepared in heterogeneous or supportedform, it is preferred to use silica as the support material.

At all times, the individual ingredients, as well as the catalystcomponents, should be protected from oxygen and moisture. Therefore, thecatalyst components and catalysts should be prepared and recovered in anoxygen and moisture free atmosphere. Preferably, therefore, thereactions are performed in the presence of a dry, inert gas such as, forexample, nitrogen or argon.

The molar ratio of metal complex: activating cocatalyst employedpreferably ranges from 1:1000 to 2:1, more preferably from 1:5 to 1.5:1,most preferably from 1:2 to 1:1. In the preferred case in which a metalcomplex is activated by trispentafluorophenylborane andtriisobutylaluminum modified methylalumoxane, the transitionmetal:boron:aluminum molar ratio is typically from 1:10:50 to 1:0.5:0.1,and most typically from about 1:3:5.

In general, the polymerization may be accomplished at conditions forZiegler-Natta or metallocene-type polymerization reactions, that is,reactor pressures ranging from atmospheric to 3500 atmospheres (354.6MPa). The reactor temperature should be greater than 80° C., typicallyfrom 100° C. to 250° C., and preferably from 100° C. to 180° C., withhigher reactor temperatures, that is, reactor temperatures greater than100° C. generally favoring the formation of lower molecular weightpolymers.

In most polymerization reactions the molar ratio ofcatalyst:polymerizable compounds employed is from 10⁻¹²:1 to 10⁻¹:1,more preferably from 10⁻⁹:1 to 10⁻⁵:1.

Solution polymerization conditions utilize a solvent for the respectivecomponents of the reaction. Preferred solvents include mineral oils andthe various hydrocarbons which are liquid at reaction temperatures.Mustrative examples of useful solvents include alkanes such as pentane,isopentane, hexane, heptane, octane and nonane, as well as mixtures ofalkanes including kerosene and Isopar E™, available from Exxon ChemicalsInc.; cycloalkanes such as cyclopentane and cyclohexane; and aromaticssuch as benzene, toluene, xylenes, ethylbenzene and diethylbenzene.

The solvent will be present in an amount sufficient to prevent phaseseparation in the reactor. As the solvent functions to absorb heat, lesssolvent leads to a less adiabatic reactor. The solvent:ethylene ratio(weight basis) will typically be from 2.5:1 to 12:1, beyond which pointcatalyst efficiency suffers. The most typical solvent:ethylene ratio(weight basis) is in the range of from 3.5:1 to 7:1.

The polymerization may be carried out as a batchwise or a continuouspolymerization process, with continuous polymerizations processes beingrequired for the preparation of substantially linear polymers. In acontinuous process, ethylene, comonomer, and optionally solvent anddiene are continuously supplied to the reaction zone and polymer productcontinuously removed therefrom.

Other Additives

The interpolymers of the present invention may also contain a number ofadditional components, such as a stabilizer, plasticizer, filler orantioxidant. Among the applicable stabilizers or antioxidants which canbe included in the adhesive composition of the present invention arehigh molecular weight hindered phenols and multifunctional phenols, suchas sulfur-containing and phosphorous-containing phenols. Hinderedphenols, known to those skilled in the art, may be described as phenoliccompounds, which also contain sterically bulky radicals in closeproximity to the phenolic hydroxyl group. Specifically, tertiary butylgroups generally are substituted onto the benzene ring in at least oneof the ortho positions relative to the phenolic hydroxyl group. Thepresence of these sterically bulky substituted radicals in the vicinityof the hydroxyl group serves to retard its stretching frequency, andcorrespondingly, its reactivity. It is this hindrance that provides thestabilizing properties of these phenolic compounds.

Representative hindered phenols include; but are not limited to:2,4,6-trialkylated monohydroxy phenols;1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-benzene;pentaerythritoltetrakis-3(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate, commerciallyavailable under the trademark IRGANOX® 1010;n-octadecyl-3(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate;4,4′-methylenebis(4-methyl-6-tert-butyl-phenol);4,4′-thiobis(6-tert-butyl-o-cresol); 2,6-di-tertbutylphenol;6-(4-hydroxyphenoxy)-2,4-bis(n-octyl-thio)-1,3,5 triazine;2-(n-octylthio)ethyl 3,5-di-tert-butyl-4-hydroxy-benzoate;di-n-octadecyl 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate; andsorbitol hexa(3,3,5-di-tert-butyl-4-hydroxy-phenyl)-propionate.

Antioxidants include, but are not limited to, butylated hydroxy anisole(“BHA”) or butylated hydroxy toluene (“BHT”) which may also be utilizedto render the formulation more thermally stable. These stabilizers andantioxidants are added in amounts ranging approximately 0.01% toapproximately 5% by weight of the formulation.

Utilizing known synergists in conjunction with the antioxidants mayfurther enhance the performance of these antioxidants. Some of theseknown synergists are, for example, thiodipropionate esters andphosphates. Chelating agents and metal deactivators, may also be used.Examples of these compounds include ethylenediaminetetraacetic acid(“EDTA”), and more preferably, its salts, anddisalicylalpropylenediamine. Distearylthiodipropionate is particularlyuseful. When added to the adhesive composition, these stabilizers, ifused, are generally present in amounts of about 0.1 to about 1.5 weightpercent, and more preferably in the range of about 0.25 to about 1.0weight percent.

The present invention also contemplates the addition of a polymericadditive to the adhesive. The polymeric additive can be selected fromthe group consisting of ethylene methyl acrylate polymers containing 10to 28 weight percent by weight methyl acrylate; ethylene acrylic acidcopolymers having an acid number of 25 to 150; polyethylene;polypropylene; poly(butene-1-co-ethylene) polymers and low molecularweight and/or low melt index ethylene n-butyl acrylate copolymers. Whensuch a polymeric additive is added, it is present in amounts up to about15 weight percent by weight of composition.

Depending on the specific end uses contemplated for formulations of theinterpolymers, other additives such as plasticizers, pigments anddyestuffs may be included. A plasticizer may be used in lieu of, or incombination with a secondary tackifier to modify viscosity and improvethe tack properties of an adhesive composition.

A dispersant can also be added to these compositions. The dispersant canbe a chemical, which may, by itself, cause the composition to bedispersed from the surface to which it has been applied, for example,under aqueous conditions. The dispersant may also be an agent which whenchemically modified, causes the composition to be dispersed from thesurface to which it has been applied. As known to those skilled in theart, examples of these dispersants include surfactants, emulsifyingagents, and various cationic, anionic or nonionic dispersants. Compoundssuch as amines, amides and their derivatives are examples of cationicdispersants. Soaps, acids, esters and alcohols are among the knownanionic dispersants. The addition of a dispersant may affect therecyclability of products to which a hot-melt adhesive may have beenapplied.

The surfactants can be chosen from a variety of known surface-activeagents. These can include nonionic compounds such as ethoxylatesavailable from commercial suppliers. Examples include alcoholethoxylates, alkylamine ethoxylates, alkylphenol ethyoxylates,octylphenol ethoxylates and the like. Other surfactants, such as anumber of fatty acid esters may be employed; for example, but notlimited to, glycerol esters, polyethyleneglycol esters and sorbitanesters.

Tackifiers

In order to formulate hot melt adhesives from the polymers of thepresent invention, the addition of tackifier is desirable to allow forbonding prior to solidifying or setting of the adhesive. An example ofthis is in high-speed cereal box sealing operations where theoverlapping flaps of the box need to adhere to one another while the hotmelt adhesive solidifies.

Such tackifying resins include aliphatic, cycloaliphatic and aromatichydrocarbons and modified hydrocarbons and hydrogenated versions;terpenes and modified terpenes and hydrogenated versions; and rosins androsin derivatives and hydrogenated versions; and mixtures thereof. Thesetackifying resins have a ring and ball softening point from 70° C. to150° C., and will typically have a viscosity at 350° F. (177° C.), asmeasured using a Brookfield viscometer, of no more than 2000 centipoise.They are also available with differing levels of hydrogenation, orsaturation, which is another commonly used term. Useful examples includeEastotac™ H-100, H-115, H-130 and H-142 from Eastman Chemical Co. inKingsport, Term., which are partially hydrogenated cycloaliphaticpetroleum hydrocarbon resins with softening points of 100° C., 115° C.and 130° C., respectively. These are available in the E grade, the Rgrade, the L grade and the W grade, indicating differing levels ofhydrogenation with E being the least hydrogenated and W being the mosthydrogenated. The E grade has a bromine number of 15, the R grade abromine number of 5, the L grade a bromine number of 3 and the W gradehas a bromine number of 1. Eastotac™H-142R from Eastman Chemical Co. hasa softening point of about 140° C. Other useful tackifying resinsinclude Escorez™5300, 5400, and 5637, partially hydrogenated aliphaticpetroleum hydrocarbon resins, and Escorez™5600, a partially hydrogenatedaromatic modified petroleum hydrocarbon resin all available from ExxonChemical Co. in Houston, Tex.; Wingtack™ Extra, which is an aliphatic,aromatic petroleum hydrocarbon resin available from Goodyear ChemicalCo. in Akron, Ohio; Hercolite™ 2100, a partially hydrogenatedcycloaliphatic petroleum hydrocarbon resin available from Hercules, Inc.in Wilmington, Del.

There are numerous types of rosins and modified rosins available withdiffering levels of hydrogenation including gum rosins, wood rosins,tall-oil rosins, distilled rosins, dimerized rosins and polymerizedrosins. Some specific modified rosins include glycerol andpentaerythritol esters of wood rosins and tall-oil rosins. Commerciallyavailable grades include, but are not limited to, Sylvatac™ 1103, apentaerytbritol rosin ester available from Arizona Chemical Co., Unitac™R-100 Lite, a pentaerydiritol rosin ester from Union Camp in Wayne,N.J., Permalyn™ 305, a erythritol modified wood rosin available fromHercules and Foral 105 which is a highly hydrogenated pentaerythritolrosin ester also available from Hercules. Sylvatac™ R-85 and 295 are 85°C. and 95° C. melt point rosin acids available from Arizona Chemical Co.and Foral AX is a 70° C. melt point hydrogenated rosin acid availablefrom Hercules, Inc. Nirez V-2040 is a phenolic modified terpene resinavailable from Arizona Chemical Co.

Another exemplary tackifier, Piccotac 115, has a viscosity at 350° F.(177° C.) of about 1600 centipoise. Other typical tackifiers haveviscosities at 350° F. (177° C.) of much less than 1600 centipoise, forinstance, from 50 to 300 centipoise.

Exemplary aliphatic resins include those available under the tradedesignations Eastotac™, Escorez™, Piccotac™, Mercures™, Wingtack™,Hi-Rez™, Quintone™, Taclirol™, etc. Exemplary polyterpene resins includethose available under the trade designations Nirez™, Piccolyte™,Wingtack™, Zonarez™, etc. Exemplary hydrogenated resins include thoseavailable under the trade designations Escorez™, Arkon™, Clearon™, etc.Exemplary mixed aliphatic-aromatic resins include those available underthe trade designations Escorez™, Regalite™, Hercures™, AR™, Imprez™,Norsolene™ M, Marukarez™, Arkon™, Quintone™, etc. Other tackifiers maybe employed, provided they are compatible with the homogeneous linear orsubstantially linear ethylene/alpha.-olefin interpolymer.

Although the present invention has been described with a certain degreeof particularity, it is to be understood that the examples below aremerely for purposes of illustrating the present invention, the scope ofthe present invention is not intended to be defined by the claims.

PREPARATION OF EXAMPLES

Unless otherwise stated, the following test methods are employed andpercentages or parts are by weight.

Density is measured in accordance with ASTM D-792. The samples areannealed at ambient conditions for 24 hours before the measurement istaken.

Comonomer content of the invention polymer is determined by NuclearMagnetic Resonance (NMR) analysis. The analysis sample is prepared byadding about 3 g of a 50/50 mixture oftetrachloroethane-d²/ortho-dichlorobenzene (to which sufficient chromiumacetylacetonate is added so the mixture is 0.025M in the chromiumcompound) to a 0.4 g sample of the polymer in a 10 mm NMR tube. Samplesare dissolved and homogenized in the tube by heating it and contents to150° C./302° F. Data is collected using a Varian Unity Plus 400 MHz NMRspectrometer, corresponding to a ¹³C resonance frequency of 100.6 MHz.Acquisition parameters are selected to ensure quantitative ¹³C dataacquisition in the presence of the chromium acetylacetonate which actsas a relaxation agent. Data is acquired using gated ¹H decoupling, 4000transients per data file, a 6 second pulse repetition delay, spectralwidth of 24,200 Hz and a file size of 64K data points with the probehead heated to 130° C./266° F.

Molecular weights are determined by gel permeation chromatography (GPC).The chromatographic system consists of either a Polymer LaboratoriesModel PL-210 or a Polymer Laboratories Model PL-220. The column andcarousel compartments are operated at 140° C. Three Polymer Laboratories10-micron Mixed-B columns are used with a solvent of 1,2,4trichlorobenzene. The samples are prepared at a concentration of 0.1 gof polymer in 50 ml of solvent. The solvent used to prepare the samplescontains 200 ppm of butylated hydroxytoluene (BHT). Samples are preparedby agitating lightly for 2 hours at 160° C. The injection volume used is100 microliters and the flow rate is 1.0 ml/min. Calibration of the GPCcolumn set is performed with narrow molecular weight distributionpolystyrene standards available from Polymer Laboratories. Thepolystyrene standard peak molecular weights are converted topolyethylene molecular weights using appropriate Mark-Houwinkcoefficients for polyethylene and polystyrene (as described by Williamsand Ward in Journal of Polymer Science, Polymer Letters, Vol. 6, (621)1968) in the equation:M _(plyethylene) =A(M _(polystyrene))^(B)where M is the molecular weight, A has a value of 0.4316 and B is equalto 1.0. Polyethylene equivalent molecular weight calculations areperformed using Viscotek TriSEC software Version 3.0.

Weight average molecular weight, M_(W), is calculated in the usualmanner according to the following formula: M_(j)=(Σw_(i)(M_(i)^(j)))^(j); where w_(i) is the weight fraction of the molecules withmolecular weight M_(i) eluting from the GPC column in fraction i, andj=1 when calculating M_(w), and j=−1 when calculating M_(n).

Melt viscosity is determined in accordance with the following procedure:Viscosity was measured according to the ASTM D 3236 method, using aBrookfield Laboratories DVII+Viscometer equipped with disposablealuminum sample chambers. The spindle used is a SC-31 hot-melt spindle,suitable for measuring viscosities in the range of from 30 to 100,000centipoise. A cutting blade is employed to cut samples into pieces smallenough to fit into the 1 inch wide, 5 inches long sample chamber. Thesample is placed in the chamber, which is in turn inserted into aBrookfield Thermosel and locked into place with bent needle-nose pliers.The sample chamber has a notch on the bottom that fits the bottom of theBrookfield Thermosel to ensure that the chamber is not allowed to turnwhen the spindle is inserted and spinning. The sample is heated to thedesired temperature (149° C./300° F. or 177° C./350° F.), withadditional sample being added until the melted sample is about 1 inchbelow the top of the sample chamber. The viscometer apparatus is loweredand the spindle submerged into the sample chamber. Lowering is continueduntil brackets on the viscometer align on the Thermosel. The viscometeris turned on, and set to a shear rate which leads to a torque reading inthe range of 30 to 60 percent. Readings are taken every minute for about15 minutes, or until the values stabilize, which final reading isrecorded.

The drop point is measured using ASTM D 3954 on a Mettler Toledo FP90Central Processor with FP83HT Dropping Point Cell.

Percent crystallinity is determined by differential scanning calorimetry(DSC) using a TA Instruments supplied model Q1000 differential scanningchromatograph. A sample of about 5 to 8 mg size is cut from the materialto be tested and placed directly in the DSC pan for analysis. For highermolecular weight materials a thin film is normally pressed from thesample, but for the samples of the present invention that preparation isnormally not necessary as they are either too sticky or flow too readilyduring pressing. Samples for testing may, however, be cut from plaquesthat are prepared and used for density testing. The sample is firstheated to 180° C. and held isothermally for 3 minutes at thattemperature to ensure complete melting (the first heat). Then the sampleis cooled at a rate of 10° C. per min to negative 60° C. and held thereisothermally for 3 minutes, after which it is again heated (the secondheat) at a rate of 10° C. per min to 150° C. and the thermogram fromthis second heat is referred to as the “second heat curve”. Thermogramsare plotted as watts/gram (energy) versus temperature.

Using heat of fusion data generated in the second heat curve (heat offusion normally computed automatically by typical commercial DSCequipment by integration of the relevant area under that heat curve) thepercent crystallinity in a sample may be calculated with the equation:Percent Cryst.=(H _(f)/292 J/g)×100,where Percent Cryst. represents the percent crystallinity, and H_(f)represents the heat of fusion of the ethylene interpolymer sample inJoules per gram (J/g).

Unless otherwise stated, melting points of samples of the interpolymersand adhesive formulations of the invention are determined from thesecond heat curves obtained from DSC as described above.

The evaluation of the adhesive properties of the invention formulationsis conducted by coating onto 40 pound Kraft paper.

The Shear Adhesion Failure Temperature (“SAFT”) test, (a commonly usedtest to evaluate adhesive performance, and well known to those versed inthe industry) is conducted using a standard SAFT test method (ASTM D4498) using 500 g weights. The tests are started at room temperature(25° C./77° F.) and the temperature increased at the average rate of 0.5degrees C./min.

Peel Adhesion Failure Temperature (“PAFT”) is conducted according toASTM D-4498 modified for peel mode and using 100 gram weights.

Samples for SAFT and PAFT testing are prepared using two sheets of 40pound Kraft paper, each of about 6×12 in (152×305 mm) dimensions. On thebottom sheet, lengthwise and separated by a gap of 1 in (25 mm), areadhered in parallel fashion two 1.75 or 2 in (45 or 51 mm) wide stripsof a one sided, pressure-sensitive tape such as masking tape. Theadhesive sample to be tested is heated to 177° C. (350° F.) and isdrizzled in an even manner down the center of the gap formed between thetape strips. Then before the adhesive can unduly thicken two glass rods,one rod riding immediately upon the tapes and shimmed on each side ofthe gap with a strip of the same tape followed by the second rod and(between the two rods) the second sheet of paper, are slid down thelength of the sheets. This is done in a fashion such that the first rodevenly spreads the adhesive in the gap between the tape strips and thesecond rod evenly compress the second sheet over the top of the gap andon top of the tape strips. Thus a single 1 inch wide strip of sampleadhesive is created, between the two tape strips, and bonding the papersheets. The sheets so bonded are cut crosswise into strips of width 1inch and length of about 3 inches, each strip having a 1×1 in (25×25 mm)adhesive sample bond in the center. The strips may then be employed inthe SAFT or PAFT, as desired.

Percent Fiber Tear on corrugated paper board stock is conductedaccording to standard industry test methods. The adhesive is heated to177° C./350° F. and is applied on the board stock cut into 1×3 in (25×76mm) rectangular sheets with the corrugated flutes running lengthwise.The adhesive to be tested is applied, running lengthwise, as about a 5mm/0.2 in wide strip and may be drawn down with a spatula or hot meltapplicator. Then a second strip is applied within 2 seconds and held,with moderate pressure, for 5 seconds to laminate. Laminated samples areconditioned for at least 24 hours at the temperature selected fortesting. A laminated sheet is held near one corner and using a spatula,one corner of one of the laminated sheets is folded back to form ahand-hold. With the laminate held as near as possible to the source ofheating or cooling in order to maintain the conditioning temperature,the folded corner is manually pulled as rapidly as possible at roughly a45 to 90 degree angle relative to each sheet's lengthwise axis to tearthe adhesive bond. The percent of torn fiber is estimated (fiber tear orFT) in 25% increments; i.e., 0%, 25%, 50%, 75% and 100%. Unlessotherwise stated, the FT test is normally repeated on five replicatesamples and the average of these five runs is reported.

TABLE 1 Commercially Available Materials Used in Evaluations IngredientSupplier Escorez 5637 ExxonMobil Chemical Company Houston, TX - aromaticmodified cycloaliphatic hydrocarbon tackifier resin with softening pointof 127-133° C. ADVANTRA ® H.B. Fuller Company St. Paul, MN - formulatedHL-9250 adhesive for carton and uncoated corrugated stocks with aviscosity at 350° F. of 860 cp and specific gravity of 0.929 g/cm³.ADVANTRA ® H.B. Fuller Company St. Paul, MN - formulated HL-9256adhesive for wrapper and coated carton stocks with a viscosity at 350°F. of 750 cP and specific gravity of 0.943 g/cm³. HL-7268 H.B. FullerCompany St. Paul, MN - formulated adhesive for bonding a variety ofsubstrates, with a viscosity at 350° F. of 960 cP HL-2835 H.B. FullerCompany St. Paul, MN - formulated adhesive with moderate speed of set,good flexibility, for bonding a variety of substrates, with a viscosityat 350° F. of 1070 cP. 80-8488 Henkel Consumer Adhesives Inc. Avon, OH -formulated adhesive for bonding a variety of substrates, with aviscosity at 350° F. of 1,080 cP. 80-8368 Henkel Consumer Adhesives Inc.Avon, OH - formulated adhesive for bonding a variety of substrates, witha viscosity at 350° F. of 970 cP.Polymer Preparation

A series of ethylene/α-olefin interpolymers were also prepared in a 1gallon oil jacketed, continuously stirred tank reactor. A magneticallycoupled agitator with. Lightning A-320 impellers provided the mixing.The reactor ran liquid full at 475 psig (3,275 kPa). Process flow was inat the bottom and out of the top. A heat transfer oil was circulatedthrough the jacket of the reactor to remove some of the heat ofreaction. At the exit of the reactor was a Micro-Motion™ flow meter thatmeasured flow and solution density. All lines on the exit of the reactorwere traced with 50 psi (344.7 kPa) steam and insulated.

Isopar E solvent and comonomer were supplied to the reactor at 30 psig(206.8 kPa) pressure. The solvent feed to the reactors was measured by aMicro-Motion™ mass flow meter. A variable speed diaphragm pumpcontrolled the solvent flow rate and increased the solvent pressure toreactor pressure. The comonomer was metered by a Micro-Motion™ mass flowmeter and flow controlled by a Research control valve. The comonomerstream was mixed with the solvent stream at the suction of the solventpump and is pumped to the reactor with the solvent. The remainingsolvent was combined with ethylene and (optionally) hydrogen anddelivered to the reactor. The ethylene stream was measured by aMicro-Motion™ mass flow meter just prior to the Research valvecontrolling flow. Three Brooks flow meter/controllers (1-200 sccm and2-100 sccm) were used to deliver hydrogen into the ethylene stream atthe outlet of the ethylene control valve.

The ethylene or ethylene/hydrogen mixture combined with thesolvent/comonomer stream at ambient temperature. The temperature of thesolvent/monomer as it enters the reactor was controlled with two heatexchangers. This stream enters the bottom of the 1 gallon continuouslystirred tank reactor.

In an inert atmosphere box, a solution of the transition metal compoundswas prepared by mixing the appropriate volumes of concentrated solutionsof each of the two components with solvent to provide the final catalystsolution of known concentration and composition. This solution wastransferred under nitrogen to a pressure vessel attached to ahigh-pressure metering pump for transport to the polymerization reactor.

In the same inert atmosphere box, solutions of the primary cocatalyst,methylbis(hydrogenatedtallowalkyl) ammoniumtetrakis(pentafluorophenyl)borate and the secondary cocatalyst, MMAOType 3A, were prepared in solvent and transferred to separate pressurevessels as described for the catalyst solution. The ratio of A1 totransition metal and B to transition metal was established bycontrolling the volumetric flow output if the individual metering pumpsto attain the molar ratios in the polymerization reactor as presented inTable 2. The multiple component catalyst system and its solvent flushalso enter the reactor at the bottom but through a different port thanthe monomer stream.

Polymerization was stopped with the addition of water into the reactorproduct line after the meter measuring the solution density. The reactoreffluent stream then entered a post reactor heater that providesadditional energy for the solvent removal flash. This flash occurs asthe effluent exits the post reactor heater and the pressure is droppedfrom 475 psig down to 10 at the reactor pressure control valve.

This flashed polymer entered a hot oil jacketed devolatilizer.Approximately 90% of the volatiles were removed from the polymer in thedevolatilizer. The volatiles exit the top of the devolatilizer. Theremaining stream is condensed with a chilled water jacketed exchangerand then enters a glycol jacket solvent/ethylene separation vessel.Solvent is removed from the bottom of the vessel and ethylene vents fromthe top. The ethylene stream is measured with a Micro-Motion mass flowmeter. This measurement of unreacted ethylene was used to calculate theethylene conversion. The polymer separated in the devolatilizer and waspumped out with a gear pump. The product is collected in lined pans anddried in a vacuum oven at 140° C. for 24 hr.

Table 2 summarizes the kinetic parameters of the catalysts used, Table 3summarizes the polymerization conditions and Table 4 the properties ofthe resulting polymers.

TABLE 2 Reactivity Ratios of Catalysts Used in the Present InventionCatalyst^(a) Reactivity Ratio^(b) CAT-1 13 CAT-2 3 CAT-3 90 CAT-4 8^(a)CAT 1 was (C₅Me₄SiMe₂N^(t)Bu)Ti( η⁴-1,3-pentadiene) preparedaccording to Example 17 of U.S. Pat. No. 5,556,928, the entiredisclosure of which patent is incorporated herein by reference. CAT 2was (1H-cyclopenta[1]-phenanthrene-2-yl)dimethyl (t-butylamido)silanetitanium dimethyl prepared according to Examples 1 and 2 of U.S.Pat. No. 5,150,297, the entire disclosure of which patent isincorporated herein by reference. CAT 3 was (C₅Me₄SiMe₂N^(t)Bu)ZrMe₂prepared according to Examples 1 and 86 of U.S. Pat. No. 5,703,187, theentire disclosure of which patent is incorporated herein by reference.CAT 4 was[N-(1,1-dimethylethyl)-1,1-dimethyl-1-[1,2,3,4,5-η)-3,4-diphenyl-2,4-cyclopentadienyl-1-yl]silanaminato(2)-κN]-dimethyl-titanium,prepared according to Examples 1 and 2 of WO 02/092610, the entiredisclosure of which patent is incorporated herein by reference.^(b)Measured at 150° C. using octene-1 as comonomer

TABLE 3 Ethylene/α-Olefin Interpolymers Preparation Conditions ReactorSolvent Ethylene Octene Hydrogen C2 B^(a)/Tr^(c) Temp Flow Flow FlowFlow Conversion Molar MMAO^(b)/Tr^(d) Mole Ratio Ex # ° C. lb/hr lb/hrlb/hr sccm (%) Ratio Molar Ratio Catalysts Catalyst r₁ ^(H)/r₁ ^(L) d 1150.32 25.20 2.68 1.25 174.48 89.47 1.21 10.07 CATS-1/2 1:1 13/3 2150.50 25.76 2.65 0.86 111.75 89.69 1.47 6.01 CATS-1/2 1:3 13/3 3 150.3825.80 2.65 0.76 113.80 90.37 1.51 6.04 CATS-1/2 1:3 13/3 4 149.88 25.772.65 0.85 150.35 80.15 1.37 5.96 CATS 1/2 1:3 13/3 5 129.73 20.87 2.651.03 97.77 90.46 1.47 5.99 CATS 1/3 1:1  13/90 6 130.03 20.81 2.65 1.0669.90 90.13 1.48 5.83 CATS 1/3  1:20  13/90 7 119.13 20.78 2.65 1.1747.98 90.03 1.49 5.93 CATS 1/3  1:20  13/90 8 149.65 25.51 2.65 1.0083.20 90.40 1.06 4.95 CATS-1/4 1:1 13/8 9 120.28 25.20 2.65 1.60 13.4590.44 1.08 4.91 CATS 1/3  1:10  13/90 10 150.20 25.60 2.65 0.73 121.9790.35 1.08 4.95 CATS 2/4 2:1  3/8 ^(a)The primary cocatalyst for allpolymerizations was Armeenium Borate,[methylbis(hydrogenatedtallowalkyl) ammonium tetrakis(pentafluorophenyl)borate prepared as in U.S. Patent #5,919,983, Ex. 2,the entire disclosure of which patent is incorporated herein byreference. ^(b)The secondary cocatalyst for all polymerizations was amodified methylalumoxane (MMAO) available from Akzo Nobel as MMAO-3A(CAS# 146905-79-10). ^(c)For Examples 1-4, 8 and 10 the term Tr refersto the total titanium content of the mixed catalyst system. For Examples5-7 and 9 the term Tr refers to the Zr content only of the mixedcatalyst system. ^(d)For Examples 1-4 and 8 it can be noted that the r₁^(H)/r₁ ^(L) ratio exceeds unity and, surprisingly (see Table 5),properties of formulations made from such interpolymers are quite goodand comparable to those from Examples 5-7 and 9-10.

TABLE 4 Properties of Ethylene/1-Octene Interpolymers Viscosity DropHeat of @ 300° F. Density M_(w)/ Wt % Mol % Point T_(m1) T_(m2) T_(m3)Fusion T_(c) 1 T_(c) 2 T_(c) 3 Ex # (cP) (g/cm³) M_(w) M_(n) M_(n) Com.Com. (° C.) (° C.) (° C.) (° C.) (J/g) % Cryst (° C.) (° C.) (° C.) 11,600 0.8941 9,570 4,180 2.29 23.40 7.10 113.3 81.2 107.0 111.1 96.2 3397.1 55.0 2 2,879 0.9040 11,200 5,030 2.23 19.80 5.81 116.9 86.3 110.3114.6 113.3 39 99.8 73.4 3 2,859 0.9083 11,300 5,220 2.16 18.30 5.30117.8 89.4 111.4 115.6 121.4 42 101.2 77.1 4 2,744 0.9092 10,900 5,0602.15 18.10 5.23 118.4 90.0 112.3 116.1 125.9 43 102.7 78.2 5 2,8040.9091 11,200 2,700 4.15 18.40 5.34 109.6 103.3 120.7 41 91.1 52.1 62,889 0.9089 12,000 2,080 5.77 18.90 5.50 112.1 95.1 107.2 125.8 43 94.77 2,684 0.9052 12,800 1,590 8.05 19.30 5.64 113.5 93.7 110.2 130.9 4597.1 81.1 8 3,047 0.9086 11,000 4,610 2.39 17.70 5.10 109.6 96.7 103.3130.2 45 93.6 54.2 9 3,113 0.9067 17,000 1,130 15.04 18.80 5.50 116.193.1 113.7 136.7 47 100.8 10 2,855 0.9084 10,800 3,940 2.74 18.30 6.30114.6 93.3 105.6 110.6 134.7 46 95.0 82.3 55.1Preparation of Adhesive Formulations with Tackifier.

Ingredients were blended in a metal container to a total weight of 100g. Tackifier resin was added into the container and allowed to heat for10 minutes with a heating mantle for temperature control. The polymerwas slowly added over 3-5 minutes. Once melted, the ingredients weremixed by hand using a metal spatula at a moderate rate of speed. Aftercomplete addition of the polymer, the adhesive was allowed to mix anadditional 15 minutes to assure uniformity. The final adhesivetemperature in all cases was 350-360° F. (˜177-182° C.). The propertiesof the resulting adhesives are summarized in Table 5 and may be comparedwith the properties of some commercially available adhesives summarizedin Table 6.

TABLE 5 Properties of Hot Melt Adhesives Made From Ethylene/OcteneInterpolymers of the Present Invention Polymer Polymer Escorez 5637Paper Tear (%)* Viscosity @ 350° F. Ex # (wt %) (wt %) 0° F. 35° F. 77°F. 120° F. 140° F. PAFT (° F.) SAFT (° F.) (cP) 1 78 22 0 25 100 100 110205 1,115 1 73 27 0 0 100 100 119 203 1,050 1 68 32 0 0 100 100 128 201950 2 78 22 0 100 100 100 75 110 211 1,060 2 73 27 0 100 100 100 100 118208 935 2 68 32 0 0 100 100 100 131 208 820 3 78 22 0 50 100 100 100 110215 1,080 3 73 27 0 25 100 100 100 132 212 980 3 68 32 0 0 100 100 100156 211 660 4 78 22 0 50 100 100 75 120 215 570 4 73 27 0 25 100 100 100122 213 500 4 68 32 0 0 100 100 100 132 211 470 5 78 22 0 100 100 100 50111 203 1,050 5 73 27 0 25 100 100 100 115 202 960 5 68 32 0 0 100 100100 118 200 860 6 78 22 0 50 100 100 100 104 203 1,000 6 73 27 0 0 100100 100 115 202 945 6 68 32 0 0 100 100 100 124 200 850 7 78 22 25 25 NM50 50 95 209 925 7 73 27 0 25 100 100 75 109 207 840 7 68 32 0 0 100 100100 127 205 755 8 83 17 0 100 NM 100 100 90 214 1300 8 78 22 0 50 NM 100100 109 208 1205 8 73 27 0 0 NM 100 100 126 207 1100 8 68 32 0 0 NM 100100 128 207 1035 9 83 17 100 100 NM 50 0 90 212 1140 9 78 22 100 100 NM100 0 90 210 1070 9 73 27 75 100 NM 100 75 90 208 930 9 68 32 0 100 NM100 100 111 208 810 10 83 17 0 100 NM 100 100 105 205 1175 10 78 22 0100 NM 100 100 112 204 1115 10 73 27 0 100 NM 100 100 126 202 1040 10 6832 0 0 NM 100 100 131 203 920 *NM = not measured

TABLE 6 Properties of Commercial Hot Melt Adhesives Viscosity @ 350° F.Paper Tear (%) Comp Ex # Commercial Name (cP) 0° F. 35° F. 77° F. 120°F. 140° F. PAFT (° F.) SAFT (° F.) 1 ADVANTRA HL-9250 860 100 100 100100 100 142 198 2 ADVANTRA HL-9256 750  0 100 100 100 100 151 192 3HL-7268 960 — — 100 100 100 144 192 4 HL-2835 1,070 100 100 100 100 100126 153 5 80-8488 1,080 — 100 100 100 100 150 176 6 80-8368 970 — 100100 100 100 142 190

We claim:
 1. A process of making an ethylene interpolymer, said processcomprising: i) contacting one or more olefinic monomers in the presenceof at least two catalysts, one having a reactivity ratio r₁ ^(H) , andthe other a reactivity ratio r₁ ^(L) , and ii) effectuating thepolymerization of the olefinic monomers in a reactor, to obtain anolefin polymer, and wherein each of r₁ ^(H) and r₁ ^(L) is from 1 to200, and r₁ ^(H) /r₁ ^(L) , is from 0.03 to 30, and/or wherein onecatalyst is capable of producing a first polymer, with a high molecularweight (M_(wH)), from the monomers, under selected polymerizationconditions, and the other catalyst is capable of producing a secondpolymer with, relative to the first polymer, a low molecular weight(M_(wL)), from the same monomers, under substantially the samepolymerization conditions, and wherein M_(wH)/M_(wL) is from 1.5 to 20,and wherein said interpolymer has a Brookfield Viscosity (measured at149° C./300° F.) from 500 to 7,000 cP, and wherein said interpolymer isa copolymer of ethylene/propylene, ethylene/1-butene,ethylene/4-methyl-1-pentene, ethylene/1-pentene, ethylene/1-hexene orethylene/1-octene.
 2. The process of claim 1, wherein the catalysts aresingle site catalysts.
 3. The process of claim 1, wherein the catalystsare metallocene catalysts.
 4. The process of claim 3, wherein at leastone of the metallocene catalysts is a constrained geometry catalyst. 5.The process of claim 4, wherein said at least one constrained geometrycatalyst is (C₅Me₄SiMe₂N^(t)Bu)Ti(η⁴-1,3-pentadiene).
 6. The process ofclaim 1, wherein the catalysts are(C₅Me₄SiMe₂N^(t)Bu)Ti(η⁴-1,3-pentadiene) and(1H-cyclopenta[1]-phenanthrene-2-yl)dimethyl(t-butylamido)silanetitanium dimethyl.
 7. The process of claim 1, wherein thecatalysts are (C₅Me₄SiMe₂N^(t)Bu)ZrMe₂ and(C₅Me₄SiMe₂N^(t)Bu)Ti(η⁴-1,3-pentadiene).
 8. The process of claim 1,wherein the catalysts are[N-(1,1-dimethylethyl)-1,1-dimethyl-1[(1,2,3,4,5-η)-3,4-diphenyl-2,4-cyclopentadienyl-1-yl]silanaminato(2)-κN]-dimethyl-titanium and (C5Me₄SiMe₂N^(t)Bu)Ti(η⁴-1,3-pentadiene).
 9. Theprocess of claim 1, wherein the catalysts are[N-(1,1-dimethylethyl)-1,1-dimethyl-1[(1,2,3,4,5-η)3,4-diphenyl-2,4-cyclopentadienyl-1-yl]silanaminato(2)-κN]-dimethyl-titanium and (1H-cyclopenta[1]-phenanthrene-2-yl)dimethyl(t-butylamido) silanetitanium dimethyl.